Adjuster for headlamp assembly

ABSTRACT

A lightweight and compact headlamp adjuster is constructed primarily from plastic materials. The adjuster may include a VHAD that is non-recalibratable after the headlamp aim is factory set. The adjuster includes an input shaft that engages a gear located within a housing. When the input shaft is rotated, a ball stud moves linearly to adjust the headlamp to which it is connected. The adjuster is not subject to over-adjustment when it includes a clutching mechanism provided by the interaction of the ball stud with the gear.

This application is a continuation application and claims priority toU.S. patent application Ser. No. 09/941,235, filed Aug. 28, 2001 nowU.S. Pat. No. 6,773,153, the disclosure of which is incorporated hereinby reference in its entirety for all purposes.

FIELD OF THE INVENTION

This invention relates generally to headlamp adjusters, and moreparticularly to a compact headlamp adjuster that can incorporate aclutching feature to prevent over-extension or over-retraction of theball stud.

BACKGROUND OF THE INVENTION

There is a trend in the automobile industry to use internally adjustablereflector headlamps. Internally adjustable reflector headlamps include areflector and bulb socket assembly enclosed within a sealed headlamphousing and lens. The orientation of the reflector within the housing isadjustable to control the direction of the light beam cast by theheadlamp. Typically, the adjustable reflector is supported by three ballstuds that extend from the rear of the headlamp housing and fit withinsockets located on the back of the reflector. A middle ball stud issecured directly to the headlamp housing to provide a fixed pivot pointfor the reflector. The other two ball studs are connected to adjustermechanisms secured to the rear of the headlamp housing. By operating theadjuster mechanisms, the ball studs can be extended and retracted tocontrol the horizontal and vertical orientation of the reflector.Examples of such adjusters include those disclosed in U.S. Pat. Nos.5,707,133 and 5,214,971 to Burton et al., U.S. Pat. No. 5,483,426 toLewis et al., U.S. Pat. No. 4,796,494 to Eckenrode et al., and U.S. Pat.No. 4,703,399 to Van Duyn et al.

United States National Highway Traffic Safety Administration (“NHTSA”)standards require that horizontal adjuster mechanisms used in connectionwith internally adjustable reflector headlamps must be eithernon-readjustable after the proper aim has been achieved or be equippedwith a non-recalibratable vehicle headlamp aiming device (“VHAD”) whichis zeroed after the proper aim has been achieved. As such, vehiclemanufacturers must either aim the lamps and provide a mechanism toprevent future readjustment, or aim the lamps and provide anon-recalibratable VHAD which is properly zeroed. One method ofproviding a non-recalibratable VHAD is disclosed in U.S. Pat. No.6,042,254 to Burton (the inventor of the present invention), thedisclosure of which is incorporated herein by reference. Several methodsof providing a non-readjustable headlamp adjuster are disclosed in U.S.Pat. No. 6,050,712 to Burton, the disclosure of which is incorporatedherein by reference.

One problem experienced when using existing adjuster devices, regardlessof whether they are in compliance with NHTSA standards, is that theysuffer one or a combination of the followings draw backs: excess cost;failure due to a lack of strength; failure due to corrosion; anunreliable air tight seal between the ball stud and adjuster housingallowing the entrance of contaminants into the headlamp; and size notbeing compact enough for some of the new aerodynamic vehicle designs inwhich space in the front of the vehicle is at a premium. When all ormost of the adjuster parts are manufactured from metal, strength is moreeasily achieved but failure due to corrosion can frequently result andplating must be used in an effort to resist corrosion. Substantialcorrosion in the threaded region is most detrimental because it cancause the threads to jam and become inoperative. Plating, while somewhathelpful, provides only limited resistance to corrosion and adds asignificant cost. When all or most of the adjuster parts aremanufactured from plastic, inadequate strength or stiffness can be anissue when trying to provide a design with a compact size. For instance,plastic gears using conventional gear tooth designs can easily strip,especially if the gears are inadequately supported within the adjusterhousing. This stripping most easily occurs when the device is “overadjusted” beyond the designed travel capabilities of the adjustermechanism. Conventional gear tooth designs use equal tooth thickness onboth gears which does not maximize stripping resistance if the materialstrength of one gear is greater than the other. Further, many existingadjuster housing designs lack adequate gear support to prevent the gearsfrom partially or fully separating under high torque conditions. Whenthe gears separate under torque the gear teeth are not fully engaged andstripping resistance is reduced. Accordingly, a need exists for anadjuster that is in accordance with NHTSA standards and is low cost,compact in design, prevents failure due to corrosion, has a reliableair-tight seal to the headlamp, and resists stripping and failure ofinternal components.

SUMMARY OF THE INVENTION

The present invention relates to a low cost and compact adjuster that isprimarily constructed from plastics, non-metal materials, or compositessuch as glass-filled nylon, and can be used in connection with anon-recalibratable VHAD or can be adapted to be non-readjustable afterfactory adjustment. As described in more detail in the detaileddescription below, and shown in the accompanying drawings, the adjustercomponents are constructed either entirely or from a high percentage ofplastic or composite materials. The adjuster has several primarycomponents, namely an input shaft, a non-recalibratable VHAD (ifdesired), a housing, a gear, and a ball stud. The housing journals thegear which in turn engages a bevel gear on the end of the input shaft.The ball stud has a toothed portion on one end that engages an internalribbed surface of the gear. When the input shaft is rotated, the gearturns causing the ball stud to rotate and move axially.

The adjuster is not subject to stripping or over-adjustment when itincludes a clutching mechanism. When the ball stud reaches the end ofthe desired travel path, the toothed portion no longer engages theribbed surface of the gear. At this point, the gear continues to rotatebut slips in relation to the ball stud. The ball stud can be made tomove in an opposite linear direction by reversing the rotation directionof the input shaft. When this is done, tangs inside the gear catch andengage the toothed portion causing it to move in the reverse direction.The adjuster housing and ball stud arrangement act to rigidly supportthe bevel gears in relation to each other to maintain full toothengagement even under high torque conditions.

The adjuster is sealed to prevent moisture from entering into theheadlamp assembly. The seal can be obtained with a gasket and O-ringthat connect to the housing, or with a molded member that is injectionmolded directly onto the housing.

In sum, the present invention represents a significant improvement overthe prior art in many ways. The adjuster of the present invention iscompact and lightweight, is efficiently and economically handled in theheadlamp or vehicle assembly process, is in conformance with NHTSAstandards, and overcomes the disadvantages of the prior art. While thepresent invention is particularly useful in headlamp assemblies, otherapplications are possible and references to use with headlamp assembliesshould not be deemed to limit the application of the present invention.In particular, the present invention may be advantageously adapted foruse where similar performance capabilities and characteristics aredesired. These and other objects and advantages of the present inventionwill become apparent from review of the detailed description, claims,and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front perspective view of one embodiment of the adjustmentmechanism of the present invention;

FIG. 2 is an exploded view of the adjustment mechanism shown in FIG. 1;

FIG. 3 is a side elevational view of the adjustment mechanism shown inFIG. 1;

FIG. 4 a front elevational view of the adjustment mechanism shown inFIG. 1;

FIG. 5 a rear elevational view of the adjustment mechanism shown in FIG.1;

FIG. 6 is a plan view of the adjustment mechanism shown in FIG. 1;

FIG. 7 a bottom view of the adjustment mechanism shown in FIG. 1;

FIG. 8 is a side sectional view of the adjustment mechanism shown inFIG. 1;

FIG. 9 is a rear perspective view of the gear used in the adjustmentmechanism of FIG. 1;

FIG. 10 is a partial front perspective view of the ball stud used in theadjustment mechanism of FIG. 1;

FIG. 11 is a side sectional view of the housing used in the adjustmentmechanism of FIG. 1;

FIG. 12 is a side sectional view of one alternative embodiment of thehousing;

FIG. 13 is a top sectional view of the adjustment mechanism of FIG. 1positioned within a headlamp assembly (shown generally, not in detail);and

FIG. 14 is a detail of one alternative embodiment of the tangs on thegear and the teeth on the ball stud.

DETAILED DESCRIPTION

FIG. 1 is a perspective view of one embodiment of the adjuster 20 havingan input shaft 22 operably connected to a ball stud 24, both of whichare generally positioned by housing 26. The exploded view of FIG. 2 is amore detailed showing of the separate components of adjuster 20. Theadditional components shown in FIG. 2 include a non-recalibratablevehicle headlamp aiming device dial 28 (hereinafter “VHAD 28”), a gear30, a gasket 32 and an O-ring 34.

Input shaft 22 is the component that is used by the automobiletechnician or vehicle owner to aim a corresponding headlamp reflector38, seen in FIG. 13. Input shaft may be constructed from die-cast zinc,other metal, from a hard plastic, or other material with similarproperties. At the top of input shaft 22 is an engagement head 50, whichmay be hexagonal as shown or other shape, and may include some type ofdepression 52 to accommodate a tool for applying torque. Shown by way ofexample is a hexagonal held with a TORX® shaped depression. A collar 56is separated from head 50 by a shaft body 54. Collar 56 has a radiallyextending pointer 58 extending therefrom for engagement with the VHAD28. Next to collar 56 are several radially extending teeth 60 that serveas a planetary gear 62 within VHAD 28. At the distal end of the shaftbody 54 from head 50 is a bevel gear 64 that engages gear 30.

Housing 26 serves to support input shaft 22 so that it properly engagesgear 30. Housing 26 may be manufactured from injection molded plasticalthough other manufacturing techniques and/or materials could be used.From the exterior of housing 26 several features can be seen. On the topsurface 70 is an annular header 72 having a number of fingers spacedthereon to accommodate VHAD 28. Header 72 may be elevated from surface70, or be a shoulder 76 as shown. From the front surface 80 projects abarrel 82. The barrel 82 has several lugs 84 or the like (i.e. screwmount, different type or number of lugs, etc.) projecting from itsexterior surface. Lugs 84 are used to mount the adjuster in the back ofthe support frame using a quarter-turn method. While four lugs 84 areshown, other numbers could be used and other means utilized for mountingthe adjuster. A flange 86 surrounds the outer circumference of structure82 and serves as a seat for gasket 32. The gasket 32 seals the adjusterto the back of the support frame and the O-ring seals the internal partof adjuster. Thus, a vapor barrier is created to prevent moisture fromcondensing on the inside of the assembly. At the distal end of barrel 82is a radial lip 88 that projects inwardly and is shaped to fit onerevolution of the spiral threads 108 on ball stud 24. Lip 88 has anoffset “break” therein so to form a stop 90, the function of which isdescribed below.

Referring to FIGS. 7 and 11, the inner surface of housing 26 has a pairof ribs 92, 94. Rib 92 is rather shallow, and may be included to providestructural support to housing 26. Rib 94 fits against the cylindricalbody 130 and the teeth on of gear 30 to keep the gear from sliding inits axial direction. The rear surface 96 of housing 26 has asemicircular notch (defined by surface 100) cut therein that also fitsagainst the cylindrical body 130. There is communication between theribbed portion of housing 26 and cavity 98 to allow ball stud 26 toextend through housing 26 and gear 30. Additional ribs or otherstructure may be included to provide structural support for the housing26 or to ensure proper journalling of the gears.

Referring to FIGS. 2 and 10, ball stud 24 is mostly hollow cylindricalmember that is preferably constructed from a tough plastic compositesuch glass-filled nylon. Ball stud 24 could be made from other types ofplastic, plastic composites or from metal and may be solid as well. Atthe front end of ball stud 24 is a ball 106 that could be of variousshapes depending on the type of socket 110 into which it is placed to besecured to the reflector, see FIG. 13. A threaded portion 108 is locatedon the main body 114 adjacent to ball 106. As seen most clearly in FIG.10, there is an abrupt stop 116 at the front end of the threaded portion108, and abrupt stop 118 at the threaded portion rear end. The stops116, 118 interact with the housing lip 88 to prevent to ball stud frombeing over adjusted in either direction. The length of the threadedportion 108 and location of the abrupt stops 116 and 118 are determinedby the desired maximum and minimum extension of the ball stud 24. Nearthe rear section of ball stud 24 is a series of teeth 120 extendingradially from the main body 114. The teeth 120 will engage an innersurface of the gear 30 as described herein. As mentioned, ball-stud 24is preferably hollow, at least in a portion of the main body 114, andpreferably up to the neck adjacent ball 106. This has the advantage ofreducing cost and weight as compared to solid ball studs. The use of arelatively large diameter hollow body resists deflection better thanother solid plastic ball studs of smaller dimension. At the rear portionof ball stud 24 nearest the end, the inner surface 122 may be hexagonal,TORX® or other shape to accommodate an assembly tool, see FIG. 5.

When engaged, gear 30 causes ball stud 24 to rotate and when disengaged,gear 30 acts as a clutching mechanism. Generally, the gear 30 slips inrelation to ball stud 24 if over-adjusted in either direction, andengages the teeth 120 of ball stud 24 during adjustment. Gear 30 can beconstructed from injection-molded plastic or other material. Referringto FIGS. 1, 2 and 9, gear 30 has several external features. At one endof cylindrical body 130 is a toothed portion having beveled teeth 132for engagement with bevel gear 64 on the input shaft. The front annularface 134 of the toothed portion is preferably flat and substantiallyperpendicular to the body 130 axis so that proper gear alignment bemaintained between gear 30 and housing 26. On the inside surface 136 ofthe toothed portion is a number of tangs 138. Tangs 138 act as smallflat springs that flex in the radial direction. Tangs 138 protrudeinwardly from surface 136, and have a stop face 140 opposite a base 142.The body of tang 138 may be arcuate in shape from base 142 to stop 140.When ball stud teeth 120 are aligned with the tangs 138, the ball stud24 is prevented from rotation by stop 116. When gear 30 rotates in thecounter-clockwise direction as indicated by arrow 166 the tangs 138slips over teeth 120 to prevent stripping or failure from overadjustment. However, the ball stud teeth 120 engage stop face 140 whenan attempt is made to move gear 30 in the opposite direction indicatedby arrow 144. More specifically, when gear 30 moves in direction 144,the flexible tangs 138 do provide enough force against the teeth 120 torotate the ball stud 24. When this happens, ball stud 120 can once againmove in a linear direction so that teeth 120 engage splines 146. Thus,tangs 138 prevent permanent disengagement of ball stud 24 and gear 30.

Referring to FIGS. 2, 8, and 9, the inner surface of gear 30 has aseries of splines 146 so that the body 130 of the gear 30 is essentiallyan elongated gear ring. Splines 146 engage the teeth 120 of ball stud24. At the rear end of gear 30, as seen in FIG. 9, are a number of tangs148 that project inwardly, similar to tangs 138. Slots 149 may beprovided in the rear end of gear 30 if additional flexibility of tangs148 is desired or may be omitted if greater stiffness is desired (thesize and depth of slots 149 can be designed to provide the desiredclipping and clutching). Once the teeth 120 are adjacent the rear innersurface 150, the gear 30 slips in relation to ball stud 24 when turnedin the direction of arrow 144, and the ball stud teeth 120 catches tangs148 when rotated in the opposite direction of arrow 144. Like tangs 138,tangs 148 are spring-like to allow slipping of the gear. Morespecifically, when gear 30 rotates in direction 144, the flexible tangs148 do not provide enough force against the teeth 120 to rotate the ballstud 24. When the gear 30 rotation is reversed, then tangs 148 do engageteeth 120 with enough force to rotate ball stud 120. When this happens,ball stud 120 once again moves in a linear direction so that teeth 120re-engage splines 146.

A detail view of an alternative embodiment of the interaction betweenthe tangs 148 on gear 30 and the teeth 120 on the ball stud 24 is shownin FIG. 14. In this embodiment, tangs 148 are provided with a notchedportion 151 which engages with a corresponding notched portion 153 onthe teeth 120 when the gear 30 is rotated to engage the tangs 148 withthe teeth 120. Using notched portion 151 on the tangs 148 and notchedportion 153 on the teeth 120 strengthens the engagement between the twoparts but does not affect the ability for the parts to slip when thegear is rotated in the opposite direction. Of course, the notchedportions could be provided in alternative shapes and dimensions.Additionally, the tangs 138 could also be provided with notched portionsin order to strengthen the engagement between tangs 138 and the teeth120.

The VHAD 28, disclosed in U.S. Pat. No. 6,042,254, incorporated hereinby reference, is a plastic component that is disposed about the inputshaft 22. VHAD 28 includes a toothed portion that is preferably athin-walled ring gear portion with internally oriented teeth (notshown). The internally oriented teeth of the ring gear portion have aslightly larger diameter than the outside diameter of the teeth 60 oninput shaft 22 so that the teeth are not engaged with each other whenthe dial is in the disengaged position. When the dial is snapped down, aprojection extending from the shoulder 76 of the adjuster distorts thethin-walled ring gear portion so as to cause a partial engagementbetween the internal teeth of the thin-walled ring gear and the teeth 60on input shaft 22. This partial engagement is on only one side of thering gear such that there is clearance between most of the teeth of thering gear and the teeth on the input shaft. Because of the partialengagement, when the input shaft 22 is rotated, the teeth 60 of theinput shaft cause the ring gear to also rotate. However, there are moreteeth on the ring gear than teeth 60 on input shaft 22. Thus, the ringgear and dial rotate at a slower rotational speed than the input shaft,and for each degree of rotation of the input shaft, there is a lesserdegree of rotation of the ring gear. This differential gives the readingof the amount of post-zeroing adjustment that has been made by referringto the location of a pointer 58 on the input shaft with respect to thezeroed position on the dial. The dial includes indicator lines 154 toindicate how much adjustment has been made since zeroing. Other types ofVHAD's could be used and reference to the VHAD disclosed in U.S. Pat.No. 6,042,254 should not be interpreted as limiting the type ofadjustment indicating devices that could be used. Alternatively, theadjuster could be adapted to be non-readjustable after factoryadjustment using on of the methods disclosed in U.S. Pat. No. 6,050,712to Burton, the disclosure of which is incorporated herein by reference,or other method.

O-ring 34 and gasket 32 are made from an elastomeric material such asrubber or the like. The purpose of these components is to prevent wateror moisture from entering the interior portion 40 of the headlampassembly 36. Thus, the gasket 32 has an inner diameter sized tocorrespond with the diameter of barrel 82, and preferably has across-section to seat against flange 86. O-ring 34 has an inner diametersized to seal between housing annular depression 102 and ball stud mainbody 114, and may have a circular cross-section. The annular depression102 in connection with the front annular face 134 of the gear 30 form agland for journaling the O-ring 34. Of course other configurations forjournaling the O-ring 34 to ensure proper sealing are possible.

Referring to FIG. 12, in an alternative embodiment to the presentinvention, O-ring 34 and gasket 32 may be replaced by a molded member174. In this embodiment, the injection molding of housing 26 is atwo-part process. First, the housing 26 is formed. The injection molddie is then changed, and molded member 174 is formed using the seconddie. Molded member 174 serves the same function as the O-ring 34 and thegasket 32 combined. Therefore it has two primary portions, namely a ringportion 176 and a gasket portion 178. A channel 180 links the ring andgasket portions 176, 178. Molded member 174 is constructed from anelastomeric sealing material, which may be injected at any point on themold where proper flow will occur to fully form ring and gasket portions176, 178. As shown in the illustrated example, the elastomeric materialis injected at or near channel 180. This alternative housing 26functions in the same manner as that of the previous embodiment, yetdoes not require a separate assembly step of fitting the O-ring andgasket to housing 26. In this alternative embodiment, the ring andgasket portions 176, 178 are substantially integral to the housing 26.

Referring to FIGS. 2, and 8, the adjuster 20 may be assembled as followsalthough other methods of assembly could be used. First, gasket 32 isplaced against flange 86, and O-ring 34 is seated into housing 26 atannular depression 102. Next, input shaft 22 is inserted into thehousing. Gear 30 is placed in the housing 26 so that the face 134captivates O-ring 34, and beveled teeth 132 are located to the forwardside of rib 94 (see FIG. 11) and so that the bevel gear 64 engages thebeveled teeth 132 of gear 30. Gear 30 is held in place by the insertionof ball stud 24. The VHAD 28 is then placed onto input shaft 22. Variousother views of the assembled adjuster can be seen in FIGS. 4-7.

In certain installations, the VHAD 28 is zeroed after initial aiming andrendered non-recalibratable thereafter. When the initial aiming of theheadlamp is being completed, the VHAD 28 is either not attached to theadjuster 20 or is disposed about the adjuster's input shaft in adisengaged storage position (a ramp lock may be provided to maintain thedial in the storage position). After the proper aim has been made, theVHAD 28 is snapped down using a one-way snap so that any furtherrotation of the input shaft 22 will also result in a pointer 58extending from the input shaft 22 indicating the adjustment that hasbeen made. As not all uses of adjusters require the use of a VHAD or anon-recalibratable VHAD, and, in certain applications, the VHAD can beentirely eliminated, a recalibratable VHAD may be used, or a devicewhich renders the adjuster non-readjustable may be used.

The assembled adjuster 20 may be operated as follows. By way of example,a clockwise torque as indicated by arrow 162 is applied to input shafthead 50. This application of torque causes the input shaft bevel gear 64to rotate in the clockwise direction, and the gear teeth 132 to which itis engaged to rotate in the direction of arrow 166 as seen in FIG. 1.Referring now to FIG. 8, this causes the ball stud 24 to move in thedirection of arrow 170, assuming that the gear splines 146 are inengagement with ball stud teeth 120. If torque is applied until the stop116 is in contact with lip stop 90 and the teeth 120 are no longer inengagement with gear splines 146, then ball stud 24 will cease to movein the direction of arrow 170. At this point, teeth 120 slip againstgear tangs 138. Movement of ball stud 24 can then only be obtained byreversing the direction of the applied torque.

One the direction of applied torque has been reversed so that the gear30 moves in the direction opposite to arrow 166 (see FIG. 1), teeth 120engage tangs 138 causing ball stud to move in the direction opposite ofarrow 170 (see FIG. 8.). Ball stud 24 can move in the direction oppositeto arrow 170 until teeth 120 are no longer in engagement with gearsplines 146 and the lip stop 90 engages thread stop 118. As before, uponcontinued application of torque, teeth 120 will slip against tangs 148.If the direction of torque is again reversed to that of direction ofarrow 162 (see FIG. 1), teeth 120 will engage tangs 148, and the ballstud 24 will once again move in the direction of arrow 170 (see FIG. 8).

The bevel gear 64 and gear 30 are held in alignment with each other sonot to deflect away or become misaligned under torque. The outerdiameter of the ball stud 24 itself is sufficiently sized to easilywithstand radial shear forces exerted upon it by gear 30 that occurunder torque. The outer diameter of the ball stud 24 in turn issupported inside and along the length of the housing barrel 82 like apeg in a hole. Gear 30 is restrained axially by annular surface 134 andgear teeth 132 are trapped within the housing surface 197 and rib 94.The inner diameter of header 72 on housing 26 serves to withstand radialforces exerted on the input shaft shoulder 198 from bevel gear 64 thatoccur under torque. Bevel gear 64 is further supported from axialmovement under force since it is trapped between the housing surface 199and cylindrical body 130 on gear 30.

The ball stud main body 114, gear annular surface 134 and housingdepression 102 form a cavity for securing o-ring 34 and preventing itfrom undesired twisting or relocation during adjustment. Hence a radialseal is created and maintained between the main body 114 diameter andthe inner diameter of the housing depression 102 that preventcontaminants from entering the headlamp.

The length of travel that the ball stud is capable of in eitherdirection is dependant upon the length of gear body 114, ball stud 24and housing barrel 82. The length of these components can be adjusted tofit the requirements of the particular headlamp assembly 36.

As shown in FIG. 13, automotive lamp assemblies 36 used as headlightstypically comprise several basic parts: a support frame 42, a headlampreflector 38, a lens 44, a bulb, and one or more adjusters 20. Thesupport frame 42 houses the headlamp reflector 38 and the bulb on apivotable mounting to allow the aim of the light to be adjusted usingthe adjuster 20. The lens 44 seals the front of the assembly 36 toprotect it from the elements assailing the front end of the vehicle andprovides an aerodynamic shape and attractive appearance. In such anautomotive lamp assembly 36, the headlamp reflector 38 mounts inside thehousing on one fixed ball joint 46 and is adjustable horizontally andvertically using adjusters 20 that interface with the reflector throughmoving ball joints (there is only one moving ball joint shown in FIG.13.). Right angle adjusters are typically used to allow the adjustmentof the headlight from an adjusting position above the installedheadlight.

Adjuster 20 can also be designed without the clutching feature at one orboth ends of the travel of the ball stud 24. Even without the inclusionof the clutching features of the present invention, the adjuster 20offers improved assembly ability, better sealing, and greater strippingresistance than conventional clutching designs. If the adjuster 20 isdesigned without clutching at the maximum extension of ball stud 24,then tangs 138 are omitted from the design of gear 30 and the splines146 extend through the inside surface 136. If the adjuster 20 isdesigned without clutching at the maximum retraction of ball stud 24,then tangs 148 are omitted from the design of the gear 30 and thesplines extend through the rear inner surface 150.

Although the invention has been herein shown and described in what isperceived to be the most practical and preferred embodiments, it is tobe understood that the invention is not intended to be limited to thespecific embodiments set forth above. Accordingly, it is recognized thatmodifications may be made by one skilled in the art of the inventionwithout departing from the spirit or intent of the invention andtherefore, the invention is to be taken as including all reasonableequivalents to the subject matter of the appended claims. Any referenceto claim elements in the singular, for example, using the article “a,”“an,” “the,” or “said,” is not to be construed as limiting the elementto the singular.

1. An adjustment mechanism comprising: an adjuster housing having aball-stud support cavity with an unthreaded portion and a threadedportion; an adjustment gear having an interior surface with a driveportion and an exterior surface with a toothed portion; a ball studhaving a threaded portion and a driven portion; at least a portion ofthe ball stud passing through the adjustment gear, the ball studjournaled at least partially within the ball stud support cavity by thethreaded portion and the unthreaded portion; and wherein the adjustmentgear is adapted to engage a bevel gear.
 2. The adjustment mechanism ofclaim 1 further comprising: an input shaft extending from the housing,the input shaft having a bevel gear at an end thereof, the bevel gear atthe end of the input shaft in engagement with the toothed portion of theadjustment gear.
 3. The adjustment mechanism of claim 2 wherein thedrive portion of the interior surface of the adjustment gear is asplined portion and the wherein the driven portion of the ball stud is asplined portion that corresponds to the splined portion of theadjustment gear.
 4. The adjustment mechanism of claim 2 furtherincluding a VHAD in communication with the input shaft.
 5. Theadjustment mechanism of claim 1 further including a gasket on anexterior surface of the housing and an O-ring surrounding at least aportion of the exterior surface of the ball stud.
 6. The adjustmentmechanism of claim 5 wherein the O-ring and gasket are integrallyover-molded to the adjuster housing.
 7. The adjustment mechanism ofclaim 1 wherein the threaded portion of the ball stud interfaces with alip on the housing such that rotation of the ball stud results in axialmovement of the ball stud.
 8. The adjustment mechanism of claim 1wherein the adjustment gear has at least one tang selectively inclutching engagement with the splined portion of the ball stud.
 9. Theadjustment mechanism of claim 1 wherein the adjuster housing is formedas part of a headlamp housing.
 10. An adjustment mechanism comprising:an adjuster housing having a ball-stud support cavity with an unthreadedportion and a threaded portion; an adjustment gear at least partiallyjournaled within the adjuster housing; an input shaft extending from thehousing, the input shaft having a bevel gear at an end thereof, thebevel gear on the end of the input shaft in engagement with theadjustment gear such that rotation of the input shaft causes acorresponding rotation of the adjustment gear; and a ball stud having athreaded portion and a driven portion, at least a portion of the ballstud passing through the adjustment gear, rotation of the adjustmentgear causing axial movement of the ball stud, the ball stud beingjournaled at least partially within the ball-stud support cavity by thethreaded portion and the unthreaded portion.
 11. The adjustmentmechanism of claim 10 further including a clutching means that includesat least one tang for selectively engaging the driven portion of theball stud.
 12. The adjustment mechanism of claim 10 further including aVHAD in communication with the input shaft.
 13. The adjustment mechanismof claim 10 wherein the driven portion of the ball stud is selectivelyengageable to a drive portion on an interior surface of the adjustmentgear, and wherein the threaded portion of the ball stud interfaces witha lip on the housing.
 14. The adjustment mechanism of claim 10 whereinat least a portion of the ball stud is hollow.
 15. The adjustmentmechanism of claim 10 wherein at least a portion of the ball stud ishexagonally shaped.
 16. The adjustment mechanism of claim 10 wherein thethreaded portion of the ball stud has a first stop at one end of thethreaded portion and a second stop at another end of the threadedportion of the ball stud, the first stop interacting with the lip on thehousing to prevent over-extension of the ball stud and the second stopinteracting with the lip on the housing to prevent over-retraction ofthe ball stud.
 17. The adjustment mechanism of claim 10 wherein theadjuster housing is formed as part of a headlamp housing.
 18. A headlampassembly comprising: a support frame having an open front portion and atleast one fixed ball stud; a lens disposed over the open front portionof the support frame; a reflector having a plurality of ball socketspositioned within the support frame and pivotably attached to the atleast one fixed ball stud; an adjuster housing with a rear surface, theadjuster housing formed into the support frame and having a gearjournaled at least partially within the adjuster housing, wherein theadjuster housing has a ball-stud support cavity with an unthreadedportion and a threaded portion; an input shaft having a bevel-toothedend, the bevel-toothed end of the input shaft engaging the exteriortoothed portion of the gear; and a moveable ball stud having a threadedportion and a splined portion, the moveable ball stud having a ball endextending from the adjuster housing into the support frame and engagedin one of the plurality of ball sockets in the reflector, wherein theball stud is journaled at least partially within the ball-stud supportcavity by the unthreaded portion and the threaded portion.
 19. Theheadlamp assembly of claim 18 further including a VHAD in communicationwith the input shaft.
 20. The headlamp assembly of claim 18 wherein theball stud is at least partially hollow.
 21. A compact adjustmentmechanism comprising: an adjuster housing having an interior portion anda cavity for supporting a ball stud, the cavity having a threadedportion and an unthreaded portion, the ball stud at least partiallyjournaled within the cavity by the threaded portion and the unthreadedportion; an adjustment gear having a drive portion and a toothedportion, wherein the ball stud has a threaded portion and a drivenportion; at least a portion of the ball stud passing through an interiorsurface of the adjustment gear such that the driven portion of the ballstud is engageable to the drive portion of the adjustment gear; an inputshaft extending from the housing, the input shaft having a bevel gear atan end thereof, the bevel gear in engagement with the toothed portion ofthe adjustment gear; and wherein rotation of the input shaft causesrotation of the bevel gear, rotation of the adjustment gear, coactionbetween the drive portion of the adjustment gear and the driven portionof the ball stud which causes a corresponding rotation of the ball stud,and axial movement of the ball stud.
 22. An adjustment mechanism for usein connection with a headlamp assembly having a support frame, theadjustment mechanism comprising: an adjuster housing having an interiorportion and a cavity for supporting a ball stud, the cavity having athreaded portion and an unthreaded portion, the ball stud at leastpartially journaled within the cavity by the threaded portion and theunthreaded portion; an adjustment gear at least partially journaledwithin the adjuster housing, wherein the adjustment gear is beveled; aninput shaft extending from the housing, the input shaft cooperating withthe adjustment gear such that rotation of the input shaft causes acorresponding rotation of the adjustment gear; a ball stud extendingfrom the adjuster housing with at least a portion thereof passingthrough the adjustment gear, rotation of the adjustment gear causingaxial movement of the ball stud; and an integrally formed sealing memberincluding a gasket portion on an exterior surface of the adjusterhousing and an O-ring portion surrounding at least a portion of the ballstud.